Monoazo dyestuffs, a composition and an ink for ink jet printing comprising them

ABSTRACT

Compounds of Formula (1) and salts and tautomers thereof, inks containing a compound of Formula (1), an ink jet printing process using the inks, substrates printed with the inks and ink jet printer cartridges containing the inks:                    
     wherein: 
     R 1  and R 2  each independently is H, optionally substituted alkyl, optionally substituted aryl or optionally substituted arylalkyl; 
     each W and each X independently is —COOH, —SO 3 H, —PO 3 H 2  or alkyl substituted by one or more groups selected from —COOH, —SO 3 H and —PO 3 H 2 ; 
     each Y and each Z independently is a substituent other than those defined for W and X; 
     a and d each independently is 1 to 5; 
     b and c each independently is 0 to 4; 
     (a+b) has a value of 5 or less; and 
     (c+d) has a value of 5 or less.

This invention relates to dyes, to inks and to their use in ink jetprinting (“IJP”). IJP is a non-impact printing technique in whichdroplets of ink are ejected through a fine nozzle onto a substratewithout bringing the nozzle into contact with the substrate.

There are many demanding performance requirements for dyes and inks usedin IJP. For example they desirably provide sharp, non-feathered imageshaving good water-fastness, light-fastness and optical density. The inksare often required to dry quickly when applied to a substrate to preventsmudging, but they should not form a crust over the tip of an ink jetnozzle because this will stop the printer from working. The inks shouldalso be stable to storage over time without decomposing or forming aprecipitate which could block the fine nozzle.

According to the present invention there is provided a compound ofFormula (1) and salts and tautomers thereof:

wherein:

R¹ and R² each independently is H, optionally substituted alkyl,optionally substituted aryl or optionally substituted arylalkyl;

each W and each X independently is —COOH, —SO₃H, —PO₃H₂ or alkylsubstituted by one or more groups selected from —COOH, —SO₃H and —PO₃H₂;

each Y and each Z independently is a substituent other than thosedefined for W and X;

a and d each independently is 1 to 5;

b and c each independently is 0 to 4;

(a+b) has a value of 5 or less; and

(c+d) has a value of 5 or less.

b and c are preferably each independently 0, 1 or 2, more preferably 0or 1.

a and d are preferably each independently 1, 2, or 3, more preferably 1or 2.

Preferably (a+b) has a value of 1, 2 or 3, more preferably 1 or 2.Preferably (c+d) has a value of 1, 2 or 3, more preferably 2 or 3.

The compounds of Formula (1) are preferably mono azo compounds (i.e.they contain only one azo (—N═N—) group).

Preferably each W and each X independently is —COOH, —SO₃H, —PO₃H₂ orC₁₋₁₀alkyl (more preferably C₁₋₆-alkyl) substituted by one, two or three(more preferably one) groups selected from —COOH, —SO₃H, and —PO₃H₂.

More preferably each W and each X independently is —COOH, —SO₃H orC₁₋₆-alkyl substituted by —COOH or —SO₃H. It is especially preferredthat each X is —COOH. It is especially preferred that each Windependently is —COOH or —SO₃H.

Preferably at least one W is ortho to the azo group (—N═N—).

Preferably Y and Z are each independently optionally substituted aryl,optionally substituted arylalkyl, halogen (especially F and Cl), nitro,cyano, —CF₃, —OR³, —NR⁴R⁵, —SR⁶, —C(O)R⁷, —C(O)OR⁸, —SO₂R⁹, —SOR¹⁰ oralkyl optionally substituted by a group other than —SO₃H, —COOH or—PO₃H₂; or

Z together with the carbon atom to which it is attached and a secondcarbon atom in the phenyl group form a 5- or 6-membered ring;

 wherein:

R³ is H, optionally substituted alkyl or optionally substituted aryl;

R⁶ is H, optionally substituted alkyl, optionally substituted aryl or agroup of the Formula (2);

R⁷, R⁸, R⁹ and R¹⁰ are each independently optionally substituted alkylor optionally substituted aryl;

R⁴ and R⁵ are each independently H, optionally substituted alkyl,optionally substituted aryl, —CO(C₁₋₆-alkyl), —CONH₂, a group of theFormula (2) or R⁴ and R⁵ together with the nitrogen to which they areattached form a 5- or 6- membered ring:

L¹ and L² each independently is —OR¹¹, —SR¹² or —NR¹³R¹⁴;

R¹¹ and R¹² each independently is H, optionally substituted aryl oroptionally substituted alkyl; and

R¹³ and R¹⁴ each independently is H, optionally substituted aryl,optionally substituted alkyl, —CO(C₁₋₆-alkyl) or —CONH₂ or R¹³ and R¹⁴together with the nitrogen to which they are attached form an optionallysubstituted morpholine or piperazine ring.

In a preferred embodiment Y and Z are each independently optionallysubstituted aryl, optionally substituted arylalkyl, halogen (especiallyF and Cl), nitro, cyano, —CF₃, —OR³, —NR⁴R⁵, —SR⁶, —C(O)R⁷, —C(O)OR⁸,—SO₂R⁹, —SOR¹⁰ or alkyl optionally substituted a group other than —SO₃H,—COOH or —PO₃H₂; wherein R³, R⁴, R⁵, R⁷, R⁸, R⁹ and R¹⁰ are ashereinbefore defined and R⁶ is H, optionally substituted alkyl oroptionally substituted aryl.

Preferably R⁷, R⁸, R⁹ and R¹⁰ are each independently optionallysubstituted alkyl.

When any of Y and Z is optionally substituted alkyl it is preferablyoptionally substituted C₁₋₁₀-alkyl, more preferably C₁₋₆alkyl optionallysubstituted by —OH, nitro, cyano, halogen (especially F or Cl), amino,—NH(C₁₋₄-hydroxyalkyl) or —NH(C₁₋₄-alkyl).

When any of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³ andR¹⁴ is optionally an substituted alkyl it is preferably optionallysubstituted C, ,₀-alkyl, more preferably optionally substitutedC₁₋₆-alkyl. Preferred optional substituents are —OH, —COOH, —SO₃H,—PO₃H₂, nitro, amino and halogen (preferably F or Cl), more especiallyCl, —OH, —COOH and —SO₃H.

When any of R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰, R¹¹, R¹², R¹³ andR¹⁴ is optionally substituted aryl it is preferably optionallysubstituted phenyl or optionally substituted naphthyl, especiallyoptionally substituted phenyl. Preferred optional substituents areC₁₋₄-alkoxy, (C₁₋₄-hydroxyalkoxy)-C₁₋₄-alkoxy-, —OH, —COOH, —SO₃H, —CF₃,amino, —NH(C₁₋₄-alkyl), —NH(C₁₋₄-hydroxyalkyl), —NH(—CO(C₁₋₄-alkyl)),halogen (especially F or Cl), nitro, —CO(C₁₋₄-alkyl), —SO₂(C₁₋₄alkyl)and C₁₋₄-alkyl optionally substituted by —OH, —COOH and —SO₃H.

When any of R¹, R², Y or Z is arylalkyl it is preferably optionallysubstituted phenyl-(alkylene)- or optionally substitutednaphthyl-(alkylene)- more preferably optionally substitutedphenyl-(C₁₋₆-alkylene)- or optionally substitutednaphthyl-(C₁₋₆-alkylene)- and especially optionally substituted benzyl.Preferred optional substituents on the arylalkyl groups are those listedabove for the aryl groups, more preferably C₁₋₄-alkyl, C₁₋₄-alkoxy,—SO₃H, —COOH, amino, nitro, F or Cl.

When Z together with the carbon atom to which it is attached and asecond carbon atom in the phenyl group form a 5- or 6-membered ring, thegroup attached to the azo group of Formula (1) is preferably asubstituted indanyl group, more preferably a group of the Formula (A):

wherein:

k is 0, 1 or 2;

W and d are as hereinbefore defined; and

each T independently is as hereinbefore defined for Z.

Preferably each T independently is C₁₋₆-alkyl or C₁₋₆-alkoxy each ofwhich is optionally substituted by —OH.

In Formula (A) k is preferably 0. Preferably d is 1 or 2. It isespecially preferred in Formula (A) that k is 0, d is 1 or 2 and atleast one W is ortho to the azo group in Formula (1).

When R⁴ and R⁵ together with the nitrogen to which they are attachedform a 5 or 6 membered ring it is preferably optionally substitutedmorpholine or optionally substituted piperazine.

Preferred optional substituents on the rings which may be formed by R⁴and R⁵, and R¹³ and R¹⁴, together with the nitrogen to which they areattached are selected from —OH, —COOH, —SO₃H, C₁₋₄-alkoxy and C₁₋₄-alkyloptionally substituted by —OH, —COOH or —SO₃H.

R⁷, R⁸, R⁹ and R¹⁰ are preferably each independently C₁₋₄-alkyl, morepreferably methyl or ethyl.

When R⁴ or R⁵ is a group of the Formula (2), the other group attached tothe nitrogen (R⁵ and R⁴ respectively) is preferably H or C₁₋₄-alkyl.

Preferably each Z and each Y is free from —COOH, —SO₃H and —PO₃H₂groups.

Preferably R¹ is H, optionally substituted C₁₋₁₀-alkyl, optionallysubstituted phenyl or optionally substituted phenyl-(C₁₋₆-alkylene),more preferably H, phenyl, benzyl or C₁₋₆-alkyl optionally substitutedby —OH, —SO₃H or —COOH, especially H or C₁₋₄-alkyl, more especially H.

Preferably R² is optionally substituted C₁₋₁₀-alkyl, optionallysubstituted phenyl or optionally substituted benzyl, more preferablyphenyl, benzyl or C₁₋₆-alkyl optionally substituted by —OH, —COOH or—SO₃H, especially C₁₋₄-alkyl, more especially methyl or ethyl.

Preferably each Y independently is C₁₋₄-alkyl.

It is especially preferred that the pyridinium group in the compounds ofFormula (1) is substituted only by one or two groups represented by X(i.e. b is 0 and a is 1 or 2 in Formula (1)). In this embodiment X ispreferably —COOH.

When a is 1 it is preferred that the group represented by X (preferably—COOH) is at the 3-position on the pyridinium ring.

In view of the forgoing preferences, a preferred compound of the Formula(1) comprises a compound of the Formula (3) and salts thereof:

wherein:

each X¹ and each W¹ independently is —COOH, —SO₃H or C₁₋₆-alkylsubstituted by —COOH or —SO₃H;

R¹⁵ is H or C₁₋₆-alkyl optionally substituted by —OH, —SO₃H or —COOH;

R¹⁶ is C₁₋₄-alkyl;

each Z¹ independently is optionally substituted phenyl, halogen(especially F and Cl), nitro, cyano, —CF₃, —OR³, —NR⁴R⁵, —SR⁶, —C(O)R⁷,—C(O)OR⁸, —SO₂R⁹, —SOR¹⁰ or alkyl optionally substituted by a groupother than —COOH, —SO₃H or —PO₃H₂;

q is 1 or 2;

t is 1 or 2; and

p is 0, 1 or 2;

wherein R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹ and R¹⁰ are as hereinbefore defined.

Preferably each X¹ is —COOH.

Preferably each W¹ is independently —COOH or —SO₃H.

Preferably each Z¹ is independently Cl, F, nitro, cyano, hydroxy,C₁₋₆-alkoxy, —CO(C₁₋₆-alkyl), —CO(C₁₋₆-hydroxyalkyl), —COO(C₁₋₄-alkyl),—NR¹⁶R¹⁷ or C₁₋₆alkyl optionally substituted by —OH, —F, —Cl or —NR ⁶R⁷, wherein R¹⁶ and R¹⁷ each independently is H, C₁₋₄-hydroxyalkyl-,—CONH₂, —CO(C₁₋₄alkyl), C₁₋₄-alkyl optionally substituted by —OH, —SO₃H,—COOH or —NH₂, or R¹⁶ and R¹⁷ together with the nitrogen to which theyare attached form a morpholine or piperazine ring. It is especiallypreferred that each Z¹ independently is C₁₋₄-alkyl optionallysubstituted by —OH, more especially methyl or ethyl.

R¹⁵ is preferably H or C₁₋₄-alkyl, more preferably H.

R¹⁶ is preferably methyl or ethyl, more preferably methyl.

It is especially preferred that q is 1 and X¹ is —COOH attached at the3-position on the pyridinium ring.

In another preferred embodiment:

q is 1;

X¹ is —COOH attached at the 3-position on the pyridinium ring;

t is 1 or 2;

each W¹ independently is —COOH or —SO₃H;

p is 0, 1 or 2; and

each Z¹ independently is Cl, —NHCO(C₁₋₄-alkyl) or C₁₋₄-alkyl optionallysubstituted by —OH.

The compounds of Formula (1) may be prepared by coupling the diazoniumsalt of an amine of the Formula (4) with approximately 1 molarequivalent of a compound of the Formula (5):

wherein R¹, R², W, X, Y, Z, a, b, c and d are as hereinbefore defined.

The coupling reaction is preferably performed at a pH in the range 6 to8, more preferably 7. Preferably the coupling reaction is performed atambient temperature.

The diazotisation of the amine of the Formula (4) is preferablyperformed in an aqueous medium at a pH below 7 in the presence of asuitable diazotising agent.

Preferably the diazotising agent is formed in situ, for example bydissolving an alkali metal nitrite (preferably sodium nitrite) in amolar excess of a suitable mineral acid (preferably HCl).

The compound of the Formula (5) may be prepared by condensing a compoundof the Formula (6) with a compound of the Formula (7):

wherein R¹, R², X, Y, a and b are as hereinbefore defined.

The condensation is preferably performed under alkaline conditions.

Preferably the condensation is performed at a temperature of from 80 to100° C.

The compound of Formula (6) is preferably prepared by condensing thecompound of the Formula (8) with the chloroacetamide of the FormulaCl—CH₂CONHR¹:

The compounds of the present invention may be in the free acid or saltform. Preferred salts are water-soluble, for example alkali metal salts,especially lithium, sodium and potassium salts, ammonium and substitutedammonium salts and mixed salts thereof. Especially preferred salts aresalts with sodium, lithium, ammonia and volatile amines, more especiallysodium salts.

The compounds of the present invention are conveniently synthesised inthe form of an alkali metal, for example Na salt. This may be convertedinto a different salt using known techniques. For example, an alkalimetal salt of a dye may be converted wholly or partially into a saltwith ammonia or an amine by dissolving an alkali metal salt of the dyein water, acidifying with a mineral acid and adjusting the pH of thesolution to pH 9 to 9.5 with ammonia or the amine and removing thealkali metal cations by dialysis. Alternatively the alkali metal ion maybe partially or wholly exchanged for an optionally substituted ammoniumion by a conventional ion exchange method.

It is to be understood that the present invention covers all tautomericforms of the compounds of Formula (1) and (3). For example the compoundof Formula (9) which is the hydrazo tautomer of the compound of Formula(1):

wherein W, X, Y, Z, R¹, R², a, b, c and d are as hereinbefore defined.

It is believed that the hydrazo tautomer of the Formula (9) predominatesover the azo form of the compound shown as Formula (1).

The present invention is intended to cover a single compound of theFormula (1) and compositions comprising two or more compounds of theFormula (1), or one or more compounds of the Formula (1) and one or moredyes other than a compound of Formula (1). Preferred compositionsinclude:

(i) a composition comprising one or more compound(s) of the Formula (1)and one or more yellow dyes other than a compound of the Formula (1);

(ii) a composition comprising one or more compound(s) of the Formula (1)and one or more black dyes; and

(iii) a composition comprising one or more compound(s) of the Formula(1), one or more black dyes and one or more yellow dyes other than acompound of the Formula (1).

Preferred yellow dyes for use in the compositions are water-soluble azoand bis azo dyes, for example C.I. Direct Yellow 86, C.I. Direct Yellow132, C.I. Direct Yellow 142, C.I. Direct Yellow 173 and C.I. Acid Yellow23.

Preferred black dyes for use in the compositions include water-solubleazo, bis azo and tris azo dyes, for example C.I. Direct Black 19, C.I.Direct Black 168, C.I. Direct Black 195, C.I. Direct Black 286 and C.I.Direct Black 287.

The hereinbefore described compositions may also comprise one or morewater-soluble cyan dyes, for example C.I. Direct Blue 199 or C.I. AcidBlue 9.

The compounds according to the present invention are useful as acolorant in inks, especially inks used in ink jet printing processes.The compounds (especially in the form of a salt with an alkali metal,ammonia or a volatile amine) exhibit a high solubility in aqueous mediaand provide bright yellow prints which exhibit a high chroma and a highlight-fastness.

According to a second aspect of the present invention there is providedan ink comprising a compound or composition according to the firstaspect of the present invention and a medium.

Preferably the medium is a liquid medium or a low melting point solid.

A preferred ink comprises:

(a) from 0.01 to 30 parts in total of one or more compound(s) of theFormula (1) or (3) or a salt thereof; and

(b) from 70 to 99.99 parts of a liquid medium or a low melting pointsolid medium;

wherein all parts are by weight and the number of parts of (a)+(b)=100.

The number of parts of component (a) is preferably from 0.1 to 20, morepreferably from 0.5 to 15, and especially from 1 to 5 parts. The numberof parts of component (b) is preferably from 99.9 to 80, more preferablyfrom 99.5 to 85, especially from 99 to 95 parts.

When the medium is a liquid, preferably component (a) is completelydissolved in component (b). Preferably component (a) has a solubility incomponent (b) at 20° C. of at least 10%. This allows the preparation ofconcentrates which may be used to prepare more dilute inks and reducesthe chance of the dye precipitating if evaporation of the liquid mediumoccurs during storage.

Preferred liquid media include water, a mixture of water and an organicsolvent and an organic solvent free from water.

When the medium comprises a mixture of water and an organic solvent, theweight ratio of water to organic solvent is preferably from 99:1 to1:99, more preferably from 99:1 to 50:50 and especially from 95:5 to80:20.

It is preferred that the organic solvent present in the mixture of waterand organic solvent is a water-miscible organic solvent or a mixture ofsuch solvents. Preferred water-miscible organic solvents includeC₁₋₆alkanols, preferably methanol, ethanol, n-propanol, isopropanol,n-butanol, sec-butanol, tert-butanol, n-pentanol, cyclopentanol andcyclohexanol; linear amides, preferably dimethylformamide ordimethylacetamide; ketones and ketone-alcohols, preferably acetone,methyl ether ketone, cyclohexanone and diacetone alcohol; water-miscibleethers, preferably tetrahydrofuran and dioxane; diols, preferably diolshaving from 2 to 12 carbon atoms, for example pentane-1,5-diol, ethyleneglycol, propylene glycol, butylene glycol, pentylene glycol, hexyleneglycol and thiodiglycol and oligo- and poly-alkyleneglycols, preferablydiethylene glycol, triethylene glycol, polyethylene glycol andpolypropylene glycol; triols, preferably glycerol and 1,2,6-hexanetriol;mono-C₁₋₄-alkyl ethers of diols, preferably mono-C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially 2-methoxyethanol,2-(2-methoxyethoxy)ethanol, 2-(2-ethoxyethoxy)-ethanol,2-[2-(2-methoxyethoxy)ethoxy]ethanol,2-[2-(2-ethoxyethoxy)-ethoxy]-ethanol and ethyleneglycol monoallylether;cyclic amides, preferably 2-pyrrolidone, N-methyl-2-pyrrolidone,N-ethyl-2-pyrrolidone, caprolactam and 1,3-dimethylimidazolidone; cyclicesters, preferably caprolactone; sulphoxides, preferably dimethylsulphoxide and sulpholane. Preferably the liquid medium comprises waterand 2 or more, especially from 2 to 8, water-soluble organic solvents.

Especially preferred water-soluble organic solvents are cyclic amides,especially 2-pyrrolidone, N-methyl-pyrrolidone and N-ethyl-pyrrolidone;diols, especially 1,5-pentane diol, ethyleneglycol, thiodiglycol,diethyleneglycol and triethyleneglycol; and mono- C₁₋₄-alkyl andC₁₋₄-alkyl ethers of diols, more preferably mono- C₁₋₄-alkyl ethers ofdiols having 2 to 12 carbon atoms, especially2-methoxy-2-ethoxy-2-ethoxyethanol.

A preferred liquid medium comprises:

(a) from 75 to 95 parts water; and

(b) from 25 to 5 parts in total of one or more solvents selected fromdiethylene glycol, 2-pyrrolidone, thiodiglycol, N-methylpyrrolidone,cyclohexanol, caprolactone, caprolactam and pentane-1,5-diol;

wherein the parts are by weight and the sum of the parts (a) and(b)=100.

Another preferred liquid medium comprises:

(a) from 60 to 80 parts water;

(b) from 2 to 20 parts diethylene glycol; and

(c) from 0.5 to 20 parts in total of one or more solvents selected from2-pyrrolidone, N-methylpyrrolidone, cyclohexanol, caprolactone,caprolactam, pentane-1,5-diol and thiodiglycol;

wherein the parts are by weight and the sum of the parts (a), (b) and(c)=100.

Examples of further suitable ink media comprising a mixture of water andone or more organic solvents are described in U.S. Pat. No. 4,963,189,U.S. Pat. No. 4,703,113, U.S. Pat. No. 4,626,284 and EP 4,251,50A.

When the liquid medium comprises an organic solvent free from water,(i.e. less than 1% water by weight) the solvent preferably has a boilingpoint of from 30° to 200° C., more preferably of from 40° to 150° C,especially from 50 to 125° C. The organic solvent may bewater-immiscible, water-miscible or a mixture of such solvents.Preferred water-miscible organic solvents are any of the hereinbeforedescribed water-miscible organic solvents and mixtures thereof.Preferred water-immiscible solvents include, for example, aliphatichydrocarbons; esters, preferably ethyl acetate; chlorinatedhydrocarbons, preferably CH₂Cl₂; and ethers, preferably diethyl ether;and mixtures thereof.

When the liquid medium comprises a water-immiscible organic solvent,preferably a polar solvent is included because this enhances solubilityof the dye in the liquid medium. Examples of polar solvents includeC₁₋₄-alcohols. In view of the foregoing preferences it is especiallypreferred that where the liquid medium is an organic solvent free fromwater it comprises a ketone (especially methyl ethyl ketone) &/or analcohol (especially a C₁₋₄-alkanol, more especially ethanol orpropanol).

The organic solvent free from water may be a single organic solvent or amixture of two or more organic solvents. It is preferred that when themedium is an organicsolvent free from water it is a mixture of 2 to 5different organic solvents. This allows a medium to be selected whichgives good control over the drying characteristics and storage stabilityof the ink.

Ink media comprising an organic solvent free from water are particularlyuseful, where fast drying times are required and particularly whenprinting onto hydrophobic and non-absorbent substrates, for exampleplastics, metal and glass.

Preferred low melting solid media have a melting point in the range from60° C. to 125° C. Suitable low melting point solids include long chainfatty acids or alcohols, preferably those with C₁₈₋₂₄ chains, andsulphonamides. The dye of Formula (1) or (3) may be dissolved in the lowmelting point solid or may be finely dispersed in it.

The ink may also contain additional components conventionally used inink jet printing inks, for example viscosity and surface tensionmodifiers, pH buffers, corrosion inhibitors, biocides, kogation reducingadditives and surfactants which may be ionic or non-ionic.

Preferably the pH of the ink according to the second aspect of thepresent invention is from 2 to 8, more preferably from 3 to 6 andespecially from 4 to 6.

The compounds according to the first aspect of the present inventionexhibit a high solubility in water. Accordingly it is preferred that theink medium is water or a mixture of water and one or more water solubleorganic solvent(s). An especially preferred ink comprises:

(a) from 0.01 to 30, more preferably 1 to 5 parts of a compound ofFormula (1) or (3);

(b) from 75 to 98, more preferably 75 to 97 parts water; and

(c) from 2 to 30, more preferably 2 to 25 parts of water-soluble organicsolvent;

wherein all parts are by weight and the sum of the parts(a)+(b)+(c)=100.

A third aspect of the invention provides a process for printing an imageon a substrate comprising applying thereto by means of an ink jetprinter an ink containing a compound of the Formula (1) or (3) or saltthereof.

The ink used in this process is preferably as defined in the secondaspect of the present invention.

The ink jet printer preferably applies the ink to the substrate in theform of droplets which are ejected through a small orifice onto thesubstrate. Preferred ink jet printers are piezoelectric ink jet printersand thermal ink jet printers. In thermal ink jet printers, programmedpulses of heat are applied to the ink in a reservoir by means of aresistor adjacent to the orifice, thereby causing the ink to be ejectedin the form of small droplets directed towards the substrate duringrelative movement between the substrate and the orifice. Inpiezoelectric ink jet printers the oscillation of a small crystal causesejection of the ink from the orifice.

The substrate is preferably paper, plastic, a textile, metal or glass,more preferably paper, an overhead projector slide or a textilematerial, especially paper.

Preferred papers are plain or treated papers which may have an acid,alkaline or neutral character. Examples of commercially availabletreated papers include HP Premium Coated Paper (available from HewlettPackard Inc), HP Photopaper (available from Hewlett Packard Inc), StylusPro 720 dpi Coated Paper, Epson Photo Quality Glossy Film (availablefrom Seiko Epson Corp.), Epson Photo Quality Glossy Paper (availablefrom Seiko Epson Corp.), Canon HR 101 High Resolution Paper (availablefrom Canon), Canon GP 201 Glossy Paper (available from Canon), and CanonHG 101 High Gloss Film (available from Canon).

A fourth aspect of the present invention provides a paper, an overheadprojector slide or a textile material printed with an ink according tothe second aspect of the present invention, or by means of a processaccording to the third aspect of the present invention.

A fifth aspect of the present invention provides an ink jet printercartridge containing an ink, wherein the ink contains a compoundaccording to the first aspect of the present invention.

The ink in the cartridge is preferably an ink according to the secondaspect of the present invention.

The invention is further illustrated by the following Examples in whichall parts and percentages are by weight unless otherwise stated.

EXAMPLE 1

Dye (1)

Dye (1) was prepared as the sodium salt as follows:

Stage (a): Preparation of Intermediate (A)

Chloroacetamide (339.4 g at 98% strength) was added toN,N-dimethylformamide (DMF) (21). To the resulting solution was addednicotinic acid (466.4 g at 98% strength) followed, by further DMF(800ml) whilst warming the mixture to 90° C. The mixture was stirred atthis temperature for 2½ hours and allowed to self cool to roomtemperature. The resulting precipitate was filtered off, washed withacetone and dried under vacuum at 50° C. to give Intermediate (A).(Yield=478 g).

Stage (b): Preparation of Intermediate (B):

Intermediate (A) (450 g) was added to ethylacetoacetate (277.2 g) andmethylated spirit 740 P (1.251). To this was added sodium hydroxidepellets (188.5 g in total dissolved in methylated spirit 740 P (800 ml)and water (840 ml)). The mixture was then heated to reflux for total of17 hours and then cooled to room temperature. The resulting solid wasfiltered off, washed with methylated spirit 740 P and dried under vacuum40° C. to give Intermediate (B). (Yield=102.2 g at 33% Strength).

Stage (c): Diazotisation and Coupling

2-carboxy-4-sulphoaniline (60.75 g at 89% strength) was dissolved inwater (600 mls) at pH 7-8 by addition of 2N NaOH (aq) and sodium nitrite(19.0 g) added. This solution was then added to a mixture of conc. HCl(162 mls) in water (200 g). The mixture was stirred at for 2 hourswhilst maintaining the temperature below 10° C. Excess nitrous acid wasthen destroyed by addition of sulphamic acid.

To above mixture was added a solution of Intermediate B (76.8 g at 33%strength) in water (800 ml). The resulting mixture, diluted to 71 intotal to effect stirring, was adjusted to pH 7 by addition of 2N NaOH.The mixture was stirred over night, salted to 15% w/v with NaCl and thepH adjusted to 5-6 by addition of conc. HCl. The resulting solid wasfiltered off washed and pulled dry in a filter.

Stage (d):

Purification

The product of stage (c) was re-dissolved in distilled water (approx.41) at pH 9.5 and desalinated by reverse osmosis. The solution was thenscreened and the water evaporated to leave the title product in the formof its sodium salt. (Yield=117 g).

EXAMPLES 2 TO 12

Further compounds of the Formula:

were prepared in the sodium salt form by diazotising the amine of theformula Ar—NH₂ shown in Table 1 and coupling the resulting diazoniumsalt with Intermediate (B) using an analogous process to that describedin Stages (c) and (d) of Example 1.

Example Amine (Ar—NH₂) 2

3

4

5

6

7

8

9

10

11

12

13

When the compounds in Examples 1 to 13 are formulated into inks andapplied to a substrate by means of an ink jet printer they providebright yellow prints which exhibit a high chroma and light-fastness.

EXAMPLE 14

Inks

Inks according to the formulations shown in Tables 2 and 3 may beprepared. In Tables 2 and 3 the Dye described in the first column is theDye made in the above examples of the same number. Numbers quoted in thesecond column onwards refer to the number of parts of the relevantingredient and all parts are by weight. The inks may be applied to paperby thermal or piezo ink jet printing.

The following abbreviations are used in Table 2 and 3:

PG=propylene glycol

DEG=diethylene glycol

NMP=N-methyl pyrrolidone

DMK=dimethylketone

MEOH=methanol

2P=2-pyrrolidone

MIBK=methylisobutyl ketone

P12=propane-1,2-diol

BDL=butane-2,3-diol

CET=cetyl ammonium bromide

PHO=Na₂HPO₄ and

TBT=tertiary butanol

TDG=thiodiglycol

GLY=glycerol

P-1,5=Pentane-1,5-diol

EXAMPLES 15 TO 25

Dye Mixtures

The dye mixtures described in Table 4 may be prepared. In row 2 thefigure in brackets refers to the number of parts by weight of the dyedescribed in the previous examples. CID means C.I.Direct, CIR meansC.I.Reactive and CIA means C.I.Acid.

TABLE 2 Dye Dye Content Water PG DEG NMP P-1,5 NaOH Na Stearate GLY MEOH2P MIBK 1 2.0 80 5 6 4 5 2 3.0 90 5 5 0.2 3 10.0 85 3 3 3 5 1 4 2.1 91 81 5 3.1 86 5 0.2 4 5 6 1.1 81 9 0.5 0.5 9 7 2.5 60 4 15 3 3 6 10 5 4 8 565 20 10 9 2.4 75 5 4 5 6 5 10 4.1 80 3 5 2 10 0.3 11 3.2 65 5 4 6 5 4 65 12 5.1 96 4 3 10.8 90 5 5 5 10.0 80 2 6 2 5 1 4 7 1.8 80 5 15 9 2.6 8411 5 1 3.3 80 2 10 2 6 2 12.0 90 7 0.3 3 1 5.4 69 2 20 2 1 3 3 12 6.0 914 5

TABLE 3 Dye Dye Content Water PG DEG NMP CET TBT TDG BDL PHO 2P P12 33.0 80 15 0.2 5 5 9.0 90 5 1.2 5 7 1.5 85 5 5 0.15 5.0 0.2 8 2.5 90 6 40.12 11 3.1 82 4 8 0.3 6 1 0.9 85 10 5 0.2 4 8.0 90 5 5 0.3 6 4.0 70 104 1 4 11 7 2.2 75 4 10 3 2 6 8 10.0 91 6 3 9 9.0 76 9 7 3.0 0.95 5 115.0 78 5 11 6 10 5.4 86 7 7 4 2.1 70 5 5 5 0.1 0.2 0.1 5 0.1 5 2 2.0 9010 1 2 88 10 3 5 78 5 12 5 1 8 70 2 8 15 5 4 10 80 8 12 5 10 80 10

TABLE 4 Example Dye 15 16 17 18 19 20 21 22 23 24 25 from Example No.1(10) 2(75) 3(60) 4(15) 1(95) 5(92) 7(11) 6(15) 8(40) 9(77) 10(63) CIDYellow 132 10  4 7 CID Yellow 142 25 5 CID Yellow 86 5 6 37 CIA Yellow23 10 10  CIA Blue 9 5 CIA Blue 307 8 CID Black 168 89 CI Food Black 280 75  30 CID Black 19 30 30 CID Black 195 81

What is claimed is:
 1. A compound of Formula (1) and salts and tautomersthereof:

wherein: R¹ and R² each independently is H, optionally substitutedalkyl, optionally substituted aryl or optionally substituted arylalkyl;each W and each X independently is —COOH, —SO₃H, —PO₃H₂ or alkylsubstituted by one or more of —COOH, —SO₃H or —PO₃H₂; each Y and each Zindependently is a substituent other than those defined for W and X; aand d each independently is 1 to 5; b and c each independently is 0 to4; (a+b) has a value of 5 or less; and (c+d) has a value of 5 or less.2. A compound according to claim 1 wherein: Y and Z are eachindependently optionally substituted aryl, optionally substitutedarylalkyl. halogen, nitro, cyano. —CF₃, —OR³, —NR⁴R⁵, —SR⁵, —C(O)R⁷,—C(O)OR⁸, —SO₂R⁹, —SOR¹⁰ or alkyl optionally substituted by a groupother than —SO₃H, —COOH or —PO₃H₂; or Z together with the carbon atom towhich it is attached and a second carbon atom in the phenyl group form a5- or 6-membered ring;  wherein: R³ is H, optionally substituted alkylor optionally substituted aryl; R⁶ is H, optionally substituted alkyl,optionally substituted aryl or a group of the Formula (2); R⁷, R⁸, R⁹and R¹⁰ are each independently optionally substituted alkyl oroptionally substituted aryl; R⁴ and R⁵ are each independently H,optionally substituted alkyl, optionally substituted aryl,—CO(C₁₋₆-alkyl), —CONH₂, a group of the Formula (2) or R⁴ and R⁵together with the nitrogen to which they are attached form a 5- or 6-membered ring:

L¹ and L² each independently is —OR¹¹, —SR¹² or —NR¹³R¹⁴; R¹¹ and R¹²each independently is H, optionally substituted aryl or optionallysubstituted alkyl; and R¹³ and R¹⁴ each independently is H, optionallysubstituted aryl, optionally substituted alkyl, —CO(C₁₋₆alkyl) or —CONH₂or R¹³ and R¹⁴ together with the nitrogen to which they are attachedform an optionally substituted morpholine or piperazine ring.
 3. Acompound according to claim 2 wherein: Y and Z are each independentlyoptionally substituted aryl, optionally substituted arylalkyl, halogen,nitro, cyano, —CF₃, —OR³, —NR⁴R⁵, —SR⁶, —C(O)R⁷, —C(O)OR⁸, —SO₂R⁹,—SOR¹⁰ or alkyl optionally substituted by a group other than —SO₃H,—COOH or —PO₃H₂; R³, R⁴, R⁵, R⁷, R⁸, R⁹ and R¹⁰ are as defined in claim2; and R⁶ is H, optionally substituted alkyl or optionally substitutedaryl.
 4. A compound according to claim 1 wherein (a+b) has a value of 1,2 or
 3. 5. A compound according to claim 1 wherein (c+d) has a value of1, 2 or
 3. 6. A compound according to claim 1 wherein b is 0 and a is 1or
 2. 7. A compound according to claim 1 wherein b is 0, a is 1 and X is—COOH attached at the 3-position in the pyridinium ring.
 8. A compoundaccording to claim 1 of the Formula (3) and salts thereof:

wherein: each X¹ and each W¹ independently is —COOH, —SO₃H or C₁₋₆-alkylsubstituted by —COOH or —SO₃H; R¹⁵ is H or C₁₋₆-alkyl optionallysubstituted by —OH, —SO₃H or —COOH; R¹⁶ is C₁₋₄-alkyl; each Z¹independently is optionally substituted phenyl, halogen, nitro, cyano,—CF₃, —OR³, —NR⁴R⁵, —SR⁶, —C(O)R⁷, —C(O)OR⁸, —SO₂R⁹, —SOR¹⁰ or alkyloptionally substituted by a group other than —COOH, —SO₃H or —PO₃H₂; qis 1 or 2; t is 1 or 2; and p is 0, 1 or 2;  wherein R³ is H, optionallysubstituted alkyl or optionally substituted aryl; R⁴ and R⁵ are eachindependently H, optionally substituted alkyl, optionally substitutedaryl, —CO(C₁₋₆-alkyl), —CONH₂, a group of the Formula (2) or R⁴ and R⁵together with the nitrogen to which they are attached form a 5- or 6-membered ring:

R⁶ is H, optionally substituted alkyl, optionally substituted aryl or agroup of the Formula (2); R⁷, R⁸, R⁹ and R¹⁰ are each independentlyoptionally substituted alkyl or optionally substituted aryl; L¹ and L²each independently is —OR¹¹, —SR¹² or —NR¹³R¹⁴; R¹¹ and R¹² eachindependently is H, optionally substituted aryl or optionallysubstituted alkyl; and R¹³ and R¹⁴ each independently is H, optionallysubstituted aryl, optionally substituted alkyl, —CO(C₁₋₆-alkyl) or—CONH₂ or R¹³ and R¹⁴ together with the nitrogen to which they areattached form an optionally substituted morpholine or piperazine ring.9. A compound according to claim 1 wherein the compound is in the formof a lithium, sodium, potassium, ammonium or substituted ammonium salt,or a mixed salt thereof.
 10. A composition comprising two or morecompounds according to claim
 1. 11. A composition comprising one or morecompounds according to claim 1 and one or more dyes other than acompound of Formula (1).
 12. An ink comprising a compound according toany one of claims 1 to 9 and a medium.
 13. An ink comprising: (a) from0.01 to 30 parts in total of one or more compound(s) according to anyone of claims 1 to 9; and (b) from 70 to 99.99 parts of a liquid mediumor a low melting point solid medium; wherein all parts are by weight andthe number of parts of (a)+(b)=100.
 14. An ink comprising: (a) from 0.01to 30, parts of a compound according to any one of claims 1 to 9; (b)from 75 to 98 parts water; and (c) from 2 to 30 parts of water-solubleorganic solvent; wherein all parts are by weight and the sum of theparts (a)+(b)+(c)=100.
 15. A process for printing an image on asubstrate comprising applying thereto by means of an ink jet printer anink containing a compound according to any one of claims 1 to
 9. 16. Apaper, an overhead projector slide or a textile material printed with anink according to claim
 12. 17. An ink jet printer cartridge containingan ink, wherein the ink contains a compound according to any one ofclaims 1 to
 9. 18. An ink comprising a composition according to claim 10and a medium.
 19. An ink comprising a composition according to claim 11and a medium.
 20. A paper, an overhead projector slide or a textilematerial printed by means of a process according to claim 15.